This invention relates to attachable eyeglasses which can be worn over normal eyeglasses.
Normal eyeglasses are worn for recovery of poor eye sight. Other special eyeglasses are used, for example, for the protection against glare and also for the protection of human eye itself. When a person wearing the normal eyeglasses wants to use other types of eyeglasses for protection against glare, various problems occur.
One who wears normal eyeglasses obtains a pair for correcting his or her eys sight. The eyeglasses also reflect that person's own tastes. In order to make eyeglasses which can be equipped both for eyesight correction and, for example, sunglasses, is very expensive. Even if one can afford this type of eyeglass, the manufacturer may run into difficulty in producing such a lens. In theory and technically, it is possible to produce such a lens, but in reality, such a job is difficult.
When a person who wears eyeglasses wants to use special eyeglasses for, for example, glare protection, first normal eyeglasses are taken off and then the sunglasses are put on. The sunglasses cannot ensure normal eye sight unless they are presecription sunglasses.
In view of these situations, "clip on glasses" are used. "Clip on glasses" are equipped with a front frame which holds glare preventive lenses and are hooked onto normal eyeglasses with a clip, when required. Thus, the wearer has both normal eyeglasses and other purpose glasses simultaneously. The prior art, however, has the following defects: (1) extra weight of the "clip on glasses" is added to the normal eyeglasses, and as a result, a total weight of almost two pairs of eyeglasses causes an oppressive sensation to the wearer; (2) when the sizes and shapes between the normal eyeglasses and the "clip on glasses" are different, this situation results in an ugly and odd look; and (3) the contact between the normal eyeglasses and the "clip on glasses" causes the scratches or damage to one or both of lenses.